[PATCH 6/6] mm: change to return bool for the MMU notifier's young flag check
Baolin Wang
baolin.wang at linux.alibaba.com
Thu Mar 19 14:24:05 AEDT 2026
The MMU notifier young flag check related functions only return whether
the young flag was set. Change the return type to bool to make the
intention clearer.
Signed-off-by: Baolin Wang <baolin.wang at linux.alibaba.com>
---
include/linux/mmu_notifier.h | 76 +++++++++++++++++-------------------
mm/internal.h | 16 ++++----
mm/mmu_notifier.c | 20 +++++-----
virt/kvm/kvm_main.c | 40 +++++++++----------
4 files changed, 72 insertions(+), 80 deletions(-)
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 3705d350c863..17f2cdc77dd5 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -97,20 +97,20 @@ struct mmu_notifier_ops {
* Start-end is necessary in case the secondary MMU is mapping the page
* at a smaller granularity than the primary MMU.
*/
- int (*clear_flush_young)(struct mmu_notifier *subscription,
- struct mm_struct *mm,
- unsigned long start,
- unsigned long end);
+ bool (*clear_flush_young)(struct mmu_notifier *subscription,
+ struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end);
/*
* clear_young is a lightweight version of clear_flush_young. Like the
* latter, it is supposed to test-and-clear the young/accessed bitflag
* in the secondary pte, but it may omit flushing the secondary tlb.
*/
- int (*clear_young)(struct mmu_notifier *subscription,
- struct mm_struct *mm,
- unsigned long start,
- unsigned long end);
+ bool (*clear_young)(struct mmu_notifier *subscription,
+ struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end);
/*
* test_young is called to check the young/accessed bitflag in
@@ -118,9 +118,9 @@ struct mmu_notifier_ops {
* frequently used without actually clearing the flag or tearing
* down the secondary mapping on the page.
*/
- int (*test_young)(struct mmu_notifier *subscription,
- struct mm_struct *mm,
- unsigned long address);
+ bool (*test_young)(struct mmu_notifier *subscription,
+ struct mm_struct *mm,
+ unsigned long address);
/*
* invalidate_range_start() and invalidate_range_end() must be
@@ -376,14 +376,12 @@ mmu_interval_check_retry(struct mmu_interval_notifier *interval_sub,
extern void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm);
extern void __mmu_notifier_release(struct mm_struct *mm);
-extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
- unsigned long start,
- unsigned long end);
-extern int __mmu_notifier_clear_young(struct mm_struct *mm,
- unsigned long start,
- unsigned long end);
-extern int __mmu_notifier_test_young(struct mm_struct *mm,
- unsigned long address);
+bool __mmu_notifier_clear_flush_young(struct mm_struct *mm,
+ unsigned long start, unsigned long end);
+bool __mmu_notifier_clear_young(struct mm_struct *mm,
+ unsigned long start, unsigned long end);
+bool __mmu_notifier_test_young(struct mm_struct *mm,
+ unsigned long address);
extern int __mmu_notifier_invalidate_range_start(struct mmu_notifier_range *r);
extern void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *r);
extern void __mmu_notifier_arch_invalidate_secondary_tlbs(struct mm_struct *mm,
@@ -403,30 +401,28 @@ static inline void mmu_notifier_release(struct mm_struct *mm)
__mmu_notifier_release(mm);
}
-static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
- unsigned long start,
- unsigned long end)
+static inline bool mmu_notifier_clear_flush_young(struct mm_struct *mm,
+ unsigned long start, unsigned long end)
{
if (mm_has_notifiers(mm))
return __mmu_notifier_clear_flush_young(mm, start, end);
- return 0;
+ return false;
}
-static inline int mmu_notifier_clear_young(struct mm_struct *mm,
- unsigned long start,
- unsigned long end)
+static inline bool mmu_notifier_clear_young(struct mm_struct *mm,
+ unsigned long start, unsigned long end)
{
if (mm_has_notifiers(mm))
return __mmu_notifier_clear_young(mm, start, end);
- return 0;
+ return false;
}
-static inline int mmu_notifier_test_young(struct mm_struct *mm,
- unsigned long address)
+static inline bool mmu_notifier_test_young(struct mm_struct *mm,
+ unsigned long address)
{
if (mm_has_notifiers(mm))
return __mmu_notifier_test_young(mm, address);
- return 0;
+ return false;
}
static inline void
@@ -552,24 +548,22 @@ static inline void mmu_notifier_release(struct mm_struct *mm)
{
}
-static inline int mmu_notifier_clear_flush_young(struct mm_struct *mm,
- unsigned long start,
- unsigned long end)
+static inline bool mmu_notifier_clear_flush_young(struct mm_struct *mm,
+ unsigned long start, unsigned long end)
{
- return 0;
+ return false;
}
-static inline int mmu_notifier_clear_young(struct mm_struct *mm,
- unsigned long start,
- unsigned long end)
+static inline bool mmu_notifier_clear_young(struct mm_struct *mm,
+ unsigned long start, unsigned long end)
{
- return 0;
+ return false;
}
-static inline int mmu_notifier_test_young(struct mm_struct *mm,
- unsigned long address)
+static inline bool mmu_notifier_test_young(struct mm_struct *mm,
+ unsigned long address)
{
- return 0;
+ return false;
}
static inline void
diff --git a/mm/internal.h b/mm/internal.h
index 0eaca2f0eb6a..3d6eba216364 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1831,10 +1831,10 @@ static inline int io_remap_pfn_range_complete(struct vm_area_struct *vma,
}
#ifdef CONFIG_MMU_NOTIFIER
-static inline int clear_flush_young_ptes_notify(struct vm_area_struct *vma,
+static inline bool clear_flush_young_ptes_notify(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep, unsigned int nr)
{
- int young;
+ bool young;
young = clear_flush_young_ptes(vma, addr, ptep, nr);
young |= mmu_notifier_clear_flush_young(vma->vm_mm, addr,
@@ -1842,30 +1842,30 @@ static inline int clear_flush_young_ptes_notify(struct vm_area_struct *vma,
return young;
}
-static inline int pmdp_clear_flush_young_notify(struct vm_area_struct *vma,
+static inline bool pmdp_clear_flush_young_notify(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmdp)
{
- int young;
+ bool young;
young = pmdp_clear_flush_young(vma, addr, pmdp);
young |= mmu_notifier_clear_flush_young(vma->vm_mm, addr, addr + PMD_SIZE);
return young;
}
-static inline int test_and_clear_young_ptes_notify(struct vm_area_struct *vma,
+static inline bool test_and_clear_young_ptes_notify(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep, unsigned int nr)
{
- int young;
+ bool young;
young = test_and_clear_young_ptes(vma, addr, ptep, nr);
young |= mmu_notifier_clear_young(vma->vm_mm, addr, addr + nr * PAGE_SIZE);
return young;
}
-static inline int pmdp_test_and_clear_young_notify(struct vm_area_struct *vma,
+static inline bool pmdp_test_and_clear_young_notify(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmdp)
{
- int young;
+ bool young;
young = pmdp_test_and_clear_young(vma, addr, pmdp);
young |= mmu_notifier_clear_young(vma->vm_mm, addr, addr + PMD_SIZE);
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index 2502474b83b6..3e3e7e727ba2 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -364,12 +364,11 @@ void __mmu_notifier_release(struct mm_struct *mm)
* unmap the address and return 1 or 0 depending if the mapping previously
* existed or not.
*/
-int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
- unsigned long start,
- unsigned long end)
+bool __mmu_notifier_clear_flush_young(struct mm_struct *mm,
+ unsigned long start, unsigned long end)
{
struct mmu_notifier *subscription;
- int young = 0, id;
+ bool young = false, id;
id = srcu_read_lock(&srcu);
hlist_for_each_entry_srcu(subscription,
@@ -384,12 +383,11 @@ int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
return young;
}
-int __mmu_notifier_clear_young(struct mm_struct *mm,
- unsigned long start,
- unsigned long end)
+bool __mmu_notifier_clear_young(struct mm_struct *mm,
+ unsigned long start, unsigned long end)
{
struct mmu_notifier *subscription;
- int young = 0, id;
+ bool young = false, id;
id = srcu_read_lock(&srcu);
hlist_for_each_entry_srcu(subscription,
@@ -404,11 +402,11 @@ int __mmu_notifier_clear_young(struct mm_struct *mm,
return young;
}
-int __mmu_notifier_test_young(struct mm_struct *mm,
- unsigned long address)
+bool __mmu_notifier_test_young(struct mm_struct *mm,
+ unsigned long address)
{
struct mmu_notifier *subscription;
- int young = 0, id;
+ bool young = false, id;
id = srcu_read_lock(&srcu);
hlist_for_each_entry_srcu(subscription,
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d0ab29672c71..6bcfc1b3021d 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -646,11 +646,11 @@ static __always_inline kvm_mn_ret_t kvm_handle_hva_range(struct kvm *kvm,
return r;
}
-static __always_inline int kvm_age_hva_range(struct mmu_notifier *mn,
- unsigned long start,
- unsigned long end,
- gfn_handler_t handler,
- bool flush_on_ret)
+static __always_inline bool kvm_age_hva_range(struct mmu_notifier *mn,
+ unsigned long start,
+ unsigned long end,
+ gfn_handler_t handler,
+ bool flush_on_ret)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
const struct kvm_mmu_notifier_range range = {
@@ -666,10 +666,10 @@ static __always_inline int kvm_age_hva_range(struct mmu_notifier *mn,
return kvm_handle_hva_range(kvm, &range).ret;
}
-static __always_inline int kvm_age_hva_range_no_flush(struct mmu_notifier *mn,
- unsigned long start,
- unsigned long end,
- gfn_handler_t handler)
+static __always_inline bool kvm_age_hva_range_no_flush(struct mmu_notifier *mn,
+ unsigned long start,
+ unsigned long end,
+ gfn_handler_t handler)
{
return kvm_age_hva_range(mn, start, end, handler, false);
}
@@ -829,10 +829,10 @@ static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
rcuwait_wake_up(&kvm->mn_memslots_update_rcuwait);
}
-static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
- struct mm_struct *mm,
- unsigned long start,
- unsigned long end)
+static bool kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
+ struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end)
{
trace_kvm_age_hva(start, end);
@@ -840,10 +840,10 @@ static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
!IS_ENABLED(CONFIG_KVM_ELIDE_TLB_FLUSH_IF_YOUNG));
}
-static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
- struct mm_struct *mm,
- unsigned long start,
- unsigned long end)
+static bool kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
+ struct mm_struct *mm,
+ unsigned long start,
+ unsigned long end)
{
trace_kvm_age_hva(start, end);
@@ -863,9 +863,9 @@ static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
return kvm_age_hva_range_no_flush(mn, start, end, kvm_age_gfn);
}
-static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
- struct mm_struct *mm,
- unsigned long address)
+static bool kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
+ struct mm_struct *mm,
+ unsigned long address)
{
trace_kvm_test_age_hva(address);
--
2.47.3
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